Pendulum UHV-AFM

Pendulum UHV-AFM is an unique design dedicated to the measurement of
extremely small forces in order of aN. In the pendulum geometry the cantilever is hoovering perpendicularly to
the sample surface, shearing the nanometer vacuum gap between tip and the sample. In this arrangement very
soft cantilevers with spring constants of k≈10-5 - 10-3 N/m can be used as force
sensors, avoiding snapping into the contact with the sample. The force sensitivity Fmin is then:

Pendulum AFM operates at cryogenic temperatures (T=5K) and typical quality factors are in the order of
Q≈105 - 106. Such high Q together with extremely small k (both at the limit for
silicon cantilevers) imply that minimal detectable energy dissipation:

is few orders of magnitude smaller as compared to standard AFM configuration.

Those tiny amount of dissipation (non-contact friction) is successfully measured by means of pendulum AFM.
The studies of nanoscale non-contact friction over phase transitions in solids are major scientific activity.
The instrument is mounted in the UHV system and measurements are carried out on atomically clean samples. The
preparation and exchanging of the cantilevers and samples are done under UHV conditions.
The microscope can be operated in a variable temperature range of 4-300K with the presence of external magnetic
field (±7 T). In addition to AFM, the microscope is also furnished with the Scanning Tunneling (STM) line.